Early work has been started by members of Professor Dame Sarah Gilbert’s team at the University of Oxford – the same scientists behind the AstraZeneca jab first rolled out in January. A source told The Independent the new vaccine was being designed with the aim of “having something on the shelf ready to scale up – if it’s needed”.
A new and modified version of the Oxford vaccine is being developed to target the Delta coronavirus variant, The Independent understands.
Although the UK’s vaccine programme was singled out as a success in a recent report which largely condemned the government for its handling of Covid-19, scientists have insisted there is still more to be done in better protecting the nation, with large pockets of the population and certain communities still not fully vaccinated.
Cases of the Delta variant are also once again surging across the UK. Some 49,156 people tested positive for Covid on Monday, a weekly rise of 22 per cent and the highest figure since the end of lockdown. The rise in prevalence comes amid waning protection levels among older age groups and fears that the booster rollout is moving too slowly.
Experts argue “there is a case” for Delta-specific vaccines for current and future vaccination programmes, with the variant now accounting for the vast majority of global infections.
Professor Eleanor Riley, an immunologist at Edinburgh University, said the biggest advantage would be to help bring widespread transmission in the UK ‘to an end”.
She said the UK’s autumn booster programme, which will ultimately see 30 million Britons offered a third vaccine dose, “would likely have much greater impact if we were using a Delta-specific vaccine.”
Given the continuing effectiveness of the original vaccine in protecting against hospitalisation and death from Covid-19, scientists at Oxford are taking a precautionary approach to developing a Delta-specific jab.
The Oxford source said it was “very early days” in the development of the new vaccine, but insisted it wouldn’t be hard to make the necessary modifications given the “plug and play” nature of the technology behind the jab.
However, the source said that even “subtle changes” introduced to the manufacturing process as a result of switching to a modified vaccine could cause significant delays and hinder the global rollout of life-saving doses, at a time when millions of people remain unvaccinated.
Professor Riley said the protection afforded by the current vaccines against severe disease and death seems to be broadly similar for all variants.
“Those of us who have been vaccinated already are no more likely to end up in hospital with the Delta variant than with the original Wuhan or Alpha strains,” she said.
However, Prof Riley said that immunity against infection – “and thus the subsequent likelihood of transmitting the virus to someone else” – is affected by the different variants, with the Oxford jab not quite as effective in preventing vaccinated people from catching Delta and “feeling a bit unwell”.
“There is therefore a case for rolling out Delta-specific vaccines,” Prof Riley said. “They are likely to be significantly better at suppressing infections in the community and may well bring widespread transmission in the UK to an end.
“This, in turn, will reduce the number of unprotected (unvaccinated or unresponsive) people being infected and ending up in hospital.”
Pfizer has already announced its plans to develop a Covid booster shot that will target Delta, while Moderna has said it would be able to easily update its vaccine to take into consideration new variants. A timeframe for the new Oxford vaccine has not been released.
Professor Robin, an immunologist at Imperial College London, said “it certainly makes sense to introduce Delta-specific vaccines” and admitted he was “surprised” there hadn’t been a desire to roll out modified jabs as part of the UK’s booster campaign.
“A variant vaccine will certainly be as good as an original Covid jab and may well be better,” he added.
Prof Riley said periodic updated boosters might be required in the months or years to come if Sars-CoV-2, the virus that causes Covid-19, continues to “throw up new highly infectious variants”.
“But it is difficult to know how often these might be needed,” she said. “At the moment it looks as though Delta is pretty much entrenched.”
Prior to their work on Delta, scientists at Oxford developed a vaccine specific to the Beta variant, which has since dropped out of circulation in many countries of the world.
